Originally Posted by synolimit

It can't drain back with oil filter installed. Many many people install with fittings on the bottom with no problems. Its better because once the filter is removed the oil will drain out of the core and you can do a real oil change and not just 83% of one.

Originally Posted by Dustin@Z1

On my personal Z's, I pull the oil cooler off every 3rd or 4th oil change to flush it out and refill it (or I do when I am prepping my Z for a track event...but since time has been limited here lately, track events have not been as frequent).

We recommend that the fittings to face upward simply because of concerns we all shared about oil starvation caused by the oil running out of the core.
Oil will drain out of the core whenever you turn the engine off and oil pressure is relieved. This will in turn cause a few things to occur:

1. The core will be drained each and every time
2. Excessive oil will fill up the oil pan
3. The oil pump will now be forced to prime the oil cooler and lines each and every time you start the car.
4. Air pockets will be likely (or possible) to form in the core.
5. It will be difficult, if not impossible, to achieve an accurate oil level reading.
6. When your engine is forced to prime the oil cooler and lines, it is then taking away vital oil pressure from critical engine components.

With all of this said, we believed that the additional hassell of having to periodically remove the core and flush it was far less costly and risky as opposed to flipping the core upside down (to facilitate easier oil changes).

The fittings are made of aluminum. I HIGHLY recommend using vaseline or some kind of lubricant whenever you are re-assembling AN fittings. Keep in mind, you are forcing aluminum against aluminum. In time, without some sort of lubricant, it will wear out the fittings and could create a leak later on down the road. A lubricant will prolong the life of the fittings, and make life easier.

ValidusVentus...you are correct. Our kit does NOT require you to move or alter the OEM PWS cooler. Even our upgraded Transmission cooler (soon to be released) still functions with the OEM PWS cooler and does not require it to be moved or modified. At the same time, all of our kits are mostly BOLT ON and require little to no drilling. Our upper oil cooler bracket does require drilling of the center core support brace, but it is optional (although highly recommended).

Each Setrab Core volumes...for those of you who are wondering...are as follows:

6 Series 19 Row 0.40 QTs
6 Series 25 Row 0.55 QTs
6 Series 34 Row 0.75 Qts

For the Z1 kit specifically, you are looking at roughly 0.34 QTs for the -10 AN Lines.

Originally Posted by spearfish25

I was working on the cars with two other Z owners today and recognized a very important issue with my oil cooler. As many people have oil coolers with the cooler fittings facing down (toward the ground, as Modshack's DIY shows), this is a potentially very important issue.

The cooler is mounted above the oil pan. This means that a good quantity of the oil in the cooler will backflow to the oil pan when the system isn't pressurized (engine is off). This has important ramifications on dipstick measurements! When the car is running, the oil pan oil level will be nearly 1 quart lower than when the engine is off. This became readily apparent after draining the oil from the pan and the cooler (disconnected one line). We refilled the system with 6 quarts (stock without cooler is 5 1/8), ran the engine for about 30 seconds to self-prime the system and then turned off the engine. Checking the oil level by dipstick immediately after shutting off the engine gave a full reading (even with top dipstick hole below H). Waiting five minutes later gave a reading well above the H. Yes, some oil drains down from the engine internals. However, the more important phenomenon here is that the oil cooler back flows to the pan if the fittings are toward the ground. Thus, if you don't keep your oil pan level near the high mark with the engine off, you may be running at or below the low mark when the engine is running with the cooler fully primed.

I brought this up with Modshack once and he dismissed the idea. He said that he got 1 quart of oil out of the cooler when he disconnected one line and drained it into a measuring cup. This may be due to the type of oil filter or sandwich plate he was using. Today I used a Purolator PureONE filter with a Mocal 200F thermostatic plate and there is back flow. Very little oil drains out when a line is disconnected with the oil pan already drained.

The takeaway message is this: If you have an oil cooler with the fittings down, an engine off dipstick reading at the H hole really means you're running with the minimum amount of oil in the sump (L-->H holes is 1 quart). Make sure you add 6 quarts!

You've been forewarned!